Mobile devices are increasingly becoming capable of communicating with various networks. This includes communication over cellular networks or over data networks such as WiFi or WiMAX. Further, some cellular networks include separate voice and data connections.
For example, the CDMA 1x/EVDO mobile system is a hybrid system that has evolved from the CDMA2000 system. EVDO stands for Evolution Data Only or Data Optimized and as suggested by this, is a data only system. EVDO systems generally allow a high transfer rate for data. Further, with a 1XEVDO System operating in hybrid mode, it is possible to receive circuit switched services, such as voice calls, even during an active data session in the EVDO System.
An always-on mobile device typically establishes and maintains a data connection over the cellular system to keep an Internet Protocol (IP) address for the mobile device, thereby permitting receipt of data quickly when data becomes available. In order to maintain the data connection and monitor for data, a frame or paging slot is designated between the network and the mobile device, which the mobile device monitors. The number of slots or frames between monitored slots or frames is the slot cycle.